A Palestinian militant has been killed during the third day of an Israeli incursion into the northern Gaza Strip.
Dozens of people have been injured in days of clashes
An Israeli helicopter gunship fired a missile into the Jabaliya refugee camp in Gaza on Friday.
Abdel Aziz Ashkar, 34, a local Hamas chief, was killed, although it is not clear if he was killed in the missile strike or was hit by a tank shell.
Troops deployed near Jabaliya three days ago to stop the firing rockets into at Israel, the Israeli army said.
It said the missile had been fired into a field that had been used by militants to shoot makeshift Qassam rockets.
Four such rockets hit the town of Sderot in the western Negev on Friday, the army said. Three Israelis were treated for shock.
A complete closure was imposed on the Palestinian territories on Thursday, which is expected to remain in place at least until the end of the Jewish New Year period in late September.
Palestinians clashed with Israeli troops for the third straight day in the Jabaliya area, Palestinian security sources and medics said.
Ten Palestinians were injured in a number of incidents, including those wounded in the missile strike, they said.
An Israeli soldier was moderately wounded by a Palestinian sniper in the camp, the army said.
At least seven Palestinians were killed and 25 injured in clashes with the Israeli troops on Thursday.
Scores of militants clashed with a column of tanks and armoured vehicles entering Jabaliya camp.
On Thursday, troops also entered the West Bank town of Jericho, where they killed a member of the Palestinian militant group al-Aqsa Martyrs Brigades.
The flare-up in violence began in the early hours of Tuesday when Israeli aircraft killed 14 Hamas militants as they were training on a Gaza football field.
The Gaza Strip and West Bank have been occupied by Israel since 1967.
Israeli Prime Minister Ariel Sharon plans to pull all
7,000 Jewish settlers from Gaza and the troops that protect them as part of his disengagement plan.
Israel will maintain control of Gaza's borders, coastline and airspace. Four West Bank settlements are also to be evacuated.
Prominent hardline Israelis have warned of "civil war" over the planned pull-out.
In a petition published on Thursday, 185 right-wingers called on soldiers and police not to help evacuate the settlers, calling it "a crime against humanity".
"[The Israeli army] was created to defend us against enemies not to go after Jews and expel them from their motherland," the petition said.
"Soldiers, officers and policemen must listen to their national conscience and not participate in operations they are bound to regret for the rest of their life."